The sequence of events which occur during development of the pineal gland and migration of the parietal eye to the parietal foramen has not been established in lizards. This project records normal development in known-age embryos of the green lizard Anolis carolinensis and several all female populations of parthenogenetic whiptail lizards (Cnemidophorus). Morphological and histological events will form the basis for a reference atlas which will mark appropriate times during ontogeny when neurosurgical techniques will be most successful. The embryological origin of parietal eyes will be established and, as experimental sets of animals mature, age related changes in the central nervous system will be recorded.